Digital still camera and method of controlling operation of same

ABSTRACT

If a telop-character recording mode is selected, then, in response to depression of a shutter-release button, the image of a subject is sensed and voice enters from a microphone for a fixed period of time so that data representing voice is obtained. Character data for indicating the content of voice by characters is generated from the data representing voice. Image data representing the image of a subject, the voice data and the character data is recorded on a memory card. When an image is reproduced, the character data is combined with the image data and the characters represented by the character data are combined with the image and displayed together with the image. The content of voice can be ascertained by telop characters even with a playback device that is incapable of outputting voice.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a digital still camera and to a method ofcontrolling the operation thereof.

2. Description of the Related Art

Digital still cameras capable of recording voice data on a recordingmedium are now well on their way to being realized. Such digital stillcameras are capable of sensing the image of a subject, recording imagedata representing the image of the subject on a memory card andrecording voice data, which represents voice contained in sensed imageof the subject, on the memory card. By reading the image data and voicedata that has been recorded on the memory card from the memory card,voice represented by the voice data can be output while the imagerepresented by the image data is being displayed.

In order to output voice, however, the device that reproduces the imagemust be equipped with a speaker or the like for outputting voice. In theabsence of a speaker, voice cannot be output even if voice data has beenrecorded on the memory card.

DISCLOSURE OF THE INVENTION

Accordingly, an object of the present invention is to make it possibleto ascertain the content of voice represented by voice data even if animage playback device does not having a function for outputting voice.

According to the present invention, the foregoing object is attained byproviding a digital still camera having an image sensing device forsensing the image of a subject and outputting image data representingthe image of the subject, and an image recording controller forrecording image data, which has been output from the image sensingdevice, on a recording medium, the camera comprising: a voice input unitfor inputting voice and outputting voice data representing voice; avoice recording controller for recording voice data, which has beenoutput from the voice input unit, on the recording medium; a characterdata generating unit for generating character data representing voicerepresented by voice data output from the voice input unit; and acharacter recording controller for recording character data, which hasbeen generated by the character data generating unit, on the recordingmedium.

The present invention provides also an operation control method suitedto the camera described above. Specifically, the invention provides amethod of controlling operation of a digital still camera having animage sensing device for sensing the image of a subject and outputtingimage data representing the image of the subject, and an image recordingcontroller for recording image data, which has been output from theimage sensing device, on a recording medium, the method comprising thesteps of: inputting voice and obtaining voice data representing voice;recording obtained voice data on the recording medium; generatingcharacter data representing voice represented by obtained voice data;and recording generated character data on the recording medium.

In accordance with the present invention, the image of a subject issensed and image data representing the image of the subject is recordedon a recording medium. Further, voice is input and data representingvoice is recorded on the recording medium. Furthermore, character data(character codes) representing this voice is generated. The generatedcharacter data also is recorded on the recording medium.

When an image is reproduced, image data that has been recorded on therecording medium is read from the medium and an image represented by theread image data is displayed. Character data also is read from therecording medium and characters represented by the character data can bedisplayed on the image. Thus, the content of voice can be ascertainedeven with an image playback device that does not possess a function suchas a voice playback function. As a result, the atmosphere represented byvoice at the time the image was captured can be grasped even with animage playback device that does not possess a function such as a voiceplayback function.

Of course, in case of an image playback device having a voice playbackfunction, voice data would be read from the recording medium and voicerepresenting the read voice data would be output.

The voice input unit may be one which inputs voice during the sensing ofthe image of a subject by the image sensing device. In this case, thecamera would further comprise a first control unit for controlling theimage recording controller, the voice recording controller and thecharacter recording controller in such a manner that at least two typesof the data among the image data, voice data and character data will berecorded on the recording medium in a form linked to each other.

Thus, mutually linked data can be found immediately.

The camera may further comprise: a first reading unit for reading imagedata and character data that has been recorded on the recording medium;a first combining unit for combining the characters, which arerepresented by the character data, with an image displayed by the imagedata that has been read by the first reading unit; and a first displayunit for displaying the image with which the characters have beencombined by the first combining unit.

Thus, characters represented by the voice data can be displayed withoutproviding an image playback device separate from the digital stillcamera.

The camera may further comprise a second combining unit for combiningcharacters, which are represented by character data that has beengenerated by the character data generating unit, with an image outputfrom the image sensing device; and a second control unit for controllingthe image recording controller and the character recording controller insuch a manner that image data representing an image with whichcharacters have been combined by the second combining unit will berecorded on the recording medium.

The camera may further comprise: a determination unit for determiningwhether the digital still camera has a voice output unit when playbackis performed; a second control unit, responsive to a determination bythe determination unit to the effect that the camera has a voice outputunit, for outputting voice, which is represented by the voice data, fromthe voice output unit and halting display of characters represented bythe character data; and a third control unit, responsive to adetermination by the determination unit to the effect that the cameradoes not have a voice output unit, for controlling a display unit so asto display the characters represented by the character data.

Since characters are not displayed when voice can be output, thecharacters will not be superimposed on an image.

The camera may further comprise a second reading unit for readingcharacter data that has been recorded on the recording medium; a seconddisplay unit for displaying characters represented by character datathat has been read by the second reading unit; and an erasure controlunit responsive to an erase command for erasing voice data, whichcorresponds to characters being displayed on the second display unit,from the recording medium.

The content of voice corresponding to characters can be ascertained byviewing the characters. Thus a user can decide whether or not to erasevoice data without listening to the voice.

The image recording controller may record image data, which has beenoutput from the image sensing device, in response to input ofpredetermined voice to the voice input unit.

Thus, a command for recording image data can be applied by inputtingpredetermined voice.

Thus, image data representing an image with which characters have beencombined can be recorded on the recording medium. Even if the imageplayback unit is not equipped with a circuit for combining an image andcharacters, an image with which characters have been combined can bedisplayed at the time of image playback.

The camera may further comprise a third reading unit for reading imagedata, which represents an image with which characters have beencombined, from the recording medium; and a second display unit fordisplaying an image represented by image data that has been read by thethird reading unit.

Thus, an image with which characters have been combined can be displayedwithout providing an image playback device separate from the digitalstill camera.

Other features and advantages of the present invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the electrical construction of adigital still camera according to an embodiment of the presentinvention;

FIG. 2 is a diagram showing the data structure of a memory cardaccording to this embodiment;

FIG. 3 is a flowchart illustrating processing executed at the time ofphotography according to this embodiment;

FIG. 4 is a flowchart illustrating processing executed at the time ofplayback according to this embodiment;

FIG. 5 shows an example of a reproduced image;

FIG. 6 is a block diagram showing the electrical construction of adigital still camera according to another embodiment of the presentinvention;

FIG. 7 is a diagram showing the data structure of a memory cardaccording to this embodiment;

FIG. 8 is a flowchart illustrating processing executed at the time ofphotography according to this embodiment; and

FIGS. 9 and 10 are flowcharts illustrating processing executed at thetime of playback according to this embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described indetail with reference to the drawings.

FIG. 1 is a block diagram showing the electrical construction of adigital still camera according to an embodiment of the presentinvention.

The overall operation of the digital still camera is controlled by acontrol circuit 20.

The digital still camera includes a shutter-release button 21 which,when pressed, applies a signal indicative thereto to the control circuit20.

The digital still camera further includes a mode setting switch 22. Thelatter makes it possible to set various modes, such as an imaging mode,voice recording mode, telop (television opaque projector) recording modeand playback mode. A signal representing the set mode is input to thecontrol circuit 20.

The digital still camera is further provided with a voice erasurefunction the details of which will be described later. A voice erasecommand from a voice erase switch 23 also is input to the controlcircuit 20.

In the imaging mode, the image of a subject is sensed and theshutter-release button 21 is pressed, whereby image data representingthe image of the subject is recorded on a memory card 30. The voicerecording mode is for recording voice data, which represents voice, onthe memory card 30 together with image data. In the telop recordingmode, data representing characters represented by the voice data isrecorded on the memory card 30 together with the image data and voicedata. The playback mode is for reproducing an image represented by theimage data that has been recorded on the recording medium.

Voice is input by a microphone 1 and a voice signal representing voiceis output. The voice signal is input to a voice recognition circuit 2and voice signal processing circuit 5.

The voice recognition circuit 2 includes an analog/digital converter forconverting the input analog voice signal to digital voice data.Characters representing voice input to the microphone 1 are recognizedfrom the digital voice data obtained by the conversion. Character codes(text code) representing the recognized characters are generated in thevoice recognition circuit 2. The generated character codes are appliedto a buffer memory 3, where the codes are stored temporarily.

The character codes are read out of the buffer memory 3 and applied toan image conversion circuit 4. The latter subjects the character codesto image-data conversion processing for expressing, in the form of animage, the characters represented by the character codes. Datarepresenting characters expressed in image form shall be referred to ascharacter data.

Character data output from the image conversion circuit 4 is applied toa recorded-data selection circuit 14 via a character data input circuit11 included in a recording controller 10.

The voice signal that has been input to the voice signal processingcircuit 5 is subjected to predetermined voice signal processing such asnoise removal processing. The voice signal processing circuit 5 alsoincludes an analog/digital converter for converting the analog voicesignal to digital voice data.

The digital voice data obtained by the conversion is applied to therecorded-data selection circuit 14 via a voice data input circuit 12.

The image of a subject is formed on the photoreceptor surface of a CCD 7by an imaging lens 6. A video signal representing the image of thesubject is output from the CCD 7 and input to a video signal processingcircuit 8. The latter subjects the video signal to predetermined videosignal processing such as gamma correction processing, color-balanceadjustment processing and analog/digital signal conversion processing.

Digital image data representing the image of the subject output from thevideo signal processing circuit 8 is input to the recorded-dataselection circuit 14 via an image data input circuit 13 included in therecording controller 10.

The recorded-data selection circuit 14 selects and outputs the appliedcharacter data, voice data or image data. The data output from therecorded-data selection circuit 14 is applied to a file informationsetting circuit 15, where the data is subjected to processing thatgenerates link data for linking the voice data and image data (e.g., asby using file names that are partially identical). The data output fromthe file information setting circuit 15 is then recorded on the memorycard 30 under the control of a memory control circuit 16.

FIG. 2 illustrates the data structure of the memory card 30.

The memory card 30 includes a header recording area for recordingmanagement data, an image data recording area for recording image data,a character data recording area for recording character data and a voicedata recording area for recording voice data.

Image data obtained by imaging is recorded in the image data recordingarea of the memory card 30 by the memory control circuit 16. Further,character data, which represents the content of voice by charactersobtained based upon voice recognition processing, is recorded in thecharacter data recording area. Furthermore, voice data is recorded inthe voice data recording area.

With reference again to FIG. 1, the playback mode is such that imagedata that has been recorded on the memory card 30 is applied to an imagedata processing circuit 31, character data that has been recorded isapplied to a character data processing circuit 32 and voice data thathas been recorded is applied to a voice data processing circuit 33.

The image data processing circuit 31 subjects the data that has beenread from the memory card 30 to predetermined image processing such asformat conversion processing that is suited to a display unit 35. Thecharacter data processing circuit 32 subjects the character data topredetermined character processing such as format conversion processingsuited to the display unit 35. Further, the voice data processingcircuit 33 subjects the voice data to predetermined processing such asformat conversion processing suited to output from a speaker 36.

The image data output from the image data processing circuit 31 and thecharacter data output from the character data processing circuit 32 isapplied to an image combining processing circuit 34. The latter subjectsthe image data and character data to combining processing in such amanner that characters represented by the character data will bedisplayed on the image represented by the image data. By applying thecombined image data to the display unit 35, the image with which thecharacters have been combined will be displayed on the display screen ofthe display unit 35.

Further, by applying the voice data output from the voice dataprocessing circuit 33 to the speaker 36, voice represented by the voicedata will be output.

FIG. 3 is a flowchart illustrating processing executed when the digitalstill camera performs photography.

Whether or not the voice recording mode has been set by the mode settingswitch 22 is checked (step 41). If the voice recording mode has not beenset (“NO” at step 41), it is considered that the camera has been setmerely to the photography mode. If the shutter-release button 21 ispressed, image data obtained as a result of imaging a subject by the CCD7 will be recorded in the image data recording area of the memory card30 (step 45). If the voice recording mode has not been set, then voicedata is not recorded on the memory card 30.

If the voice recording mode has been set (“YES” at step 41), thenwhether the telop recording mode has been set is checked (step 42). Ifthe telop recording mode has been set (“YES” at step 42), then, inresponse to depression of the shutter-release button 21, the image ofthe subject is sensed by the CCD 7 and image data representing the imageof the subject is obtained and, moreover, input of voice by themicrophone 1 starts. Input of voice is performed for a fixed period oftime starting from depression of the shutter-release button 21.

Voice data representing voice is obtained, in the manner set forthabove, from the voice signal output by the microphone 1. In the teloprecording mode, character data representing characters which indicatethe content of voice represented by the voice signal also is generated.

Thus, in the telop recording mode, image data representing the image ofa subject, voice data representing voice and character data forrepresenting the content of voice by characters are obtained. Theseitems of image data, voice data and character data are selectedsuccessively by the recorded-data selection circuit 14 and recorded onthe memory card 30. The obtained items of image data, voice data andcharacter data are recorded in the image data recording area, voice datarecording area and character data recording area, respectively, of thememory card 30 (step 44). It goes without saying that data indicatingthe corresponding relationship among the corresponding items of imagedata, voice data and character data is recorded in the header area ofthe memory card 30, as described above.

If the voice recording mode has been set but the telop recording modehas not (“NO” at step 42), voice is input by the microphone 1 but voicerecognition processing by the voice recognition circuit 2 is notexecuted. Accordingly, character data representing characters indicativeof the content of voice is not obtained. Image data representing theimage of the subject is recorded in the image data recording area ofmemory card 30 and voice data is recorded in the voice data recordingarea of memory card 30 (step 43).

In the embodiment set forth above, image data or the like is recorded onthe memory card 30 in response to depression of the shutter-releasebutton 21. However, an arrangement may be adopted in which image data orthe like is recorded on the memory card 30 in response to input ofpredetermined voice to the microphone 1. In this case, voice datarepresenting voice that triggers recording of image data would be storedin a prescribed memory beforehand and image data would be recorded onthe memory card 30 in response to a match between voice datarepresenting entered voice and the voice data that has been stored.

FIG. 4 is a flowchart illustrating processing executed by the digitalstill camera at the time of playback.

Image data is read out of the memory card 30 loaded in the digital stillcamera, and is given to the display unit 35 via the image dataprocessing circuit 31 and image combining processing circuit 34. Theimage represented by the image data that has been read out is displayedon the display screen of the display unit 35. While observing the imagedisplayed on the display screen of the display unit 35, the user selectsan image to be reproduced [it goes without saying that the digital stillcamera is provided with a frame selection switch (not shown) or the likefor selecting a playback image] (step 51).

On the basis of the link data that has been recorded in the headerrecording area of the memory card 30, it is determined whether voicedata corresponding to the image data representing the selected image hasbeen recorded in the voice data recording area of the memory card 30(step 52).

If voice data corresponding to the selected image data has not beenrecorded on the memory card 30 (“NO” at step 52), then it is construedthat the selected image data was captured by the simple image mode. Theimage represented by the selected image data is displayed on the displayscreen of the display unit 35 (step 56) without output of voice.

If voice data corresponding to the selected image data has been recordedon the memory card 30 (“YES” at step 52), then it is determined whethercharacter data corresponding to the image data has been recorded on thememory card 30 (step 53).

If both voice data and character data corresponding to the image datahas been recorded on the memory card 30 (“YES” at both steps 52 and 53),then the voice data and character data corresponding to the selectedimage data is read out of the memory card 30. The items of image data,character data and voice data that have been read out are applied to theimage data processing circuit 31, character data processing circuit 32and voice data processing circuit 33, respectively. As described above,various processing is executed and the items of image data and voicedata are combined in the image combining processing circuit 34. Theimage data with which the character data has been combined is applied tothe display unit 35. As a result, an image combined with telopcharacters 37, which are represented by the character data, is displayedon the display screen of the display unit 35, as shown in FIG. 5.Further, voice data is applied to the speaker 36 in conformity with thedisplay of the image so that voice conforming to the telop characters 37is output (step 55).

If there is no character data corresponding to image data (“NO” at step53), image data that has been read out of the memory card 30 is appliedto the display unit 35 so that the image is displayed. Since there is nocharacter data corresponding to the read image data, telop charactersare not displayed. Since there is voice data corresponding to the readimage data, voice represented by this voice data is output from thespeaker 36 (step 54).

Furthermore, it is determined whether a voice erase command has beenapplied by the voice erase switch 23 (step 57). In a case where telopcharacters are being displayed when a voice erase command is applied(“YES” at step 57), voice data representing voice corresponding to thesetelop characters is erased from the memory card 30 (step 58). Thecontent of voice can be checked by observing the telop characters.Unnecessary voice can be erased from the memory card 30 withoutlistening to it.

In the embodiment described above, the digital still camera is providedwith the speaker 36 and therefore voice represented by voice data isoutput. It goes without saying, however, that voice will not be outputif the speaker 36 has not been provided. Since telop charactersindicating the content of voice are displayed on the image even if theplayback device is not provided with a speaker, it is still possible toascertain the content of voice.

Further, in the embodiment described above, character data representingcharacters in the form of an image has been recorded on the memory card30. However, character codes may be recorded on the memory card 30.

FIGS. 6 to 9 illustrate another embodiment of the present invention.According to the above-described embodiment, character data is combinedwith image data when an image is reproduced. With the embodiment shownin FIGS. 6 to 9, however, image data is combined with character data atthe time of recording and the image data with which the character datahas been combined is recorded on the memory card 30.

FIG. 6 is a block diagram showing the electrical construction of thedigital still camera according to this embodiment. Components identicalwith those shown in FIG. 1 are designated by like reference charactersand need not be described again. FIG. 7 illustrates the data structureof the memory card 30.

FIG. 8 is a flowchart illustrating processing executed when photographyis performed using the digital still camera performs shown in FIG. 6,and FIG. 9 is a flowchart illustrating processing executed when playbackis performed using the digital still camera shown in FIG. 6. Processingsteps identical with those shown in FIGS. 3 and 4 are designated by likestep numbers and need not be described again.

Items of image data, voice data and character data are obtained in thetelop recording mode (“YES” at step 42 in FIG. 8) in a manner similar tothat of the above-described embodiment. These items of image data, voicedata and character data are applied to a data combining circuit 24. Thelatter combines the character data with the image data, whereby there isobtained image data representing an image with which telop charactershave been combined (step 46 in FIG. 8).

The memory card 30 has the header recording area, image data recordingarea and voice data recording area.

Image data with which the character data has been combined is recordedin the image data recording area of memory card 30. Further, voice datais recorded in the voice data recording area (step 47 in FIG. 8). Thus,voice data alone is not recorded on the memory card 30.

Image data with which character data has thus been combined is read outof the memory card 30 and applied to the display unit 35 via thecharacter data processing circuit 32. At playback, the image with whichtelop characters have been combined can be displayed on the displayscreen of the display unit 35 (steps 55, 56A in FIG. 9) withoutexecuting processing for combining the character data with the imagedata. Further, it goes without saying that if voice data is present,then voice is output by applying the voice data to the speaker 36 (step55 in FIG. 9).

This embodiment is useful when a device exclusively for playback doesnot have an image combining function. That is, when the playback devicedoes not have an image combining function, telop characters cannot becombined with and displayed on an image. In this embodiment, however,image data with which telop characters have already been combined isproduced in advance and recorded on the memory card 30. At playback,image combining processing is unnecessary. This means that image datawith which telop characters have been combined can be displayed evenwith a playback device not having an image combining function.

Though each of the above-described circuits is implemented by hardware,some or all of these circuits may be implemented by software.

FIG. 10 is a flowchart illustrating processing executed when playback isperformed by this digital still camera.

In a manner similar to that described above, a playback image isselected (step 61). It is then determined whether the digital stillcamera has a speaker (step 62).

If the camera has a speaker (“YES” at step 62), voice is output from thespeaker and an image without telop characters is displayed (step 63). Ifthe camera does not have a speaker (“NO” at step 62), voice output ishalted and an image with telop characters is displayed (step 64). Whenthe camera has a speaker, telop characters are not displayed. This meansthat telop characters will not interfere with viewing of the image.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

1. A digital still camera having an image sensing device for sensing animage of a subject and outputting image data representing the image ofthe subject, and an image recording controller for recording image dataoutput from the image sensing device, on a recording medium, comprising:a mode selection unit for selecting a voice recording mode or acharacter recording mode; a voice input unit for inputting a voice andoutputting voice data representing the voice; a voice recordingcontroller for recording the voice data output from said voice inputunit on the recording medium in response to a selection of the voicerecording mode by said mode selection unit; a character data generatingunit for generating character data representing the voice data outputfrom said voice input unit; a character recording controller forrecording the character data generated by said character data generatingunit on the recording medium in response to a selection of the characterrecording mode by said mode selection unit; a determination unit fordetermining whether the digital still camera has a voice output unitwhen playback is performed; a second control unit, responsive to adetermination by said determination unit that the camera has said voiceoutput unit, for outputting the voice by the voice data to said voiceoutput unit and halting display of characters represented by thecharacter data; and a third control unit, responsive to a determinationby said determination unit that the camera does not have said voiceoutput unit, for controlling a display unit so as to display thecharacters represented by the character data.
 2. A digital still camerahaving an image sensing device for sensing an image of a subject andoutputting image data representing the image of the subject, and animage recording controller for recording image data output from theimage sensing device, on a recording medium, comprising: a voice inputunit to enable input of voice and to enable output of voice datarepresenting the voice; a voice recording controller to enable recordingthe voice data output from said voice input unit on the recordingmedium; a character data generating unit to enable generating characterdata representing the voice data output from said voice input unit; acharacter recording controller to enable recording the character datagenerated by said character data generating unit on the recordingmedium; a determination unit to enable determining whether the digitalstill camera has a voice output unit when playback is performed; and acontrol unit, responsive to a determination by said determination unitthat the camera has said voice output unit, to enable output of thevoice represented by the voice data to said voice output unit and toenable halting display of characters represented by the character data.3. A digital still camera having an image sensing device for sensing animage of a subject and outputting image data representing the image ofthe subject, and an image recording controller for recording image dataoutput from the image sensing device, on a recording medium, comprising:a voice input unit to enable input of voice and to enable output ofvoice data representing the voice; a voice recording controller toenable recording the voice data output from said voice input unit on therecording medium; a character data generating unit to enable generatingcharacter data representing the voice data output from said voice inputunit; a character recording controller to enable recording the characterdata generated by said character data generating unit on the recordingmedium; a determination unit to enable determining whether the digitalstill camera has a voice output unit when playback is performed; and acontrol unit, responsive to a determination by said determination unitthat the camera does not have said voice output unit, to enablecontrolling a display unit so as to display characters represented bythe character data.